List of unstable synonyms and unstable related words.
adrift, afloat, alternating, ambiguous, amorphous, borderline, brittle, buoyant, canted, capricious, changeable, changeful, changing, choppy, corruptible, crumbling, dangerous, deciduous, decrepit, desultory, deviable, deviating, deviative, deviatory, dickey, different, disintegrating, disorderly, divaricate, divergent, diversified, diversiform, dizzy, doubtful, dubious, dying, eccentric, effervescent, elastic, ephemeral, erose, erratic, evanescent, fading, fast and loose, fickle, fitful, fleeting, flickering, flighty, flitting, fluctuant, fluctuating, fluid, fly-by-night, flying, fragile, frail, freakish, fugacious, fugitive, giddy, hazardous, heeling, ill-balanced, impermanent, impetuous, impulsive, inconsistent, inconstant, indecisive, indefinite, infirm, insecure, insubstantial, irregular, irresolute, irresponsible, jagged, jerky, leaning, listing, lopsided, lubricious, mazy, mercurial, mobile, momentary, moody, mortal, motley, moving, mutable, nonconformist, nondurable, nonpermanent, nonstandard, nonuniform, off-balance, overbalanced, passing, perilous, perishable, pluralistic, poor, poorish, precarious, protean, provisional, ragged, rambling, resilient, restless, risky, rocky, rootless, rotten, rotten at, rough, roving, scatterbrained, shaky, shapeless, short-lived, shuffling, slippery, spasmodic, spineless, sporadic, suspect, temperamental, temporal, temporary, tentative, tergiversating, ticklish, top-heavy, tottery, transient, transitive, transitory, treacherous, tricky, unaccountable, unbalanced, uncertain, uncontrolled, undecided, undependable, undisciplined, undurable, unenduring, unequable, unequal, uneven, unfaithworthy, unfirm, unfixed, unhealthy, unorthodox, unpredictable, unreliable, unrestrained, unsafe, unsettled, unsolid, unsound, unstable as water, unstaid, unsteadfast, unsteady, unsturdy, unsubstantial, unsure, unsystematic, untrustworthy, ununiform, vacillating, vagrant, variable, variegated, variform, various, varying, vicissitudinary, vicissitudinous, volatile, wandering, wanton, wavering, wavery, wavy, wayward, weak, whimsical, wishy-washy, wobbly